Question

Use the VSEPR theory to predict the shape of each of the following molecules:

Which molecules are Bent?
a) Ammonia (NH₃)
b) Silane (SiH₄)
c) Hydrogen Selenide (H₂Se)
d) Carbon Tetraiodide (CI₄)

Answer 1

Only Hydrogen Selenide (H₂Se) is predicted to have a bent shape according to the VSEPR theory, due to its two bonded pairs and two lone pairs of electrons on the selenium atom.

Step-by-step explanation:

According to the Valence Shell Electron Pair Repulsion (VSEPR) theory, the shape of a molecule is determined by the repulsion between electron pairs in the valence shell of the central atom. Here's how it applies to the molecules in question:

• Ammonia (NH₃) - This molecule has three bonded pairs and one lone pair of electrons on the nitrogen atom, resulting in a trigonal pyramidal shape, which is not bent.
• Silane (SiH₄) - With four bonded pairs and no lone pairs on the silicon atom, this molecule has a tetrahedral shape, which is also not bent.
• Hydrogen Selenide (H₂Se) - This molecule has two bonded pairs and two lone pairs of electrons on the selenium atom, resulting in a bent shape due to the larger repulsion by the lone pairs.
• Carbon Tetraiodide (CI₄) - With four bonded pairs and no lone pairs on the carbon atom, the shape is tetrahedral, and not bent.

Therefore, out of the listed molecules, only Hydrogen Selenide (H₂Se) is bent.